<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>block</title>

    {% block extcss %}
    {% endblock %}
</head>
<body>
    <h2>父模板</h2>
    <hr>
    {% block head %}
    {% endblock %}

    <hr>
    {% block content %}
        <button>父模板中的content</button>
    {% endblock %}

    <hr>
    {% block foot %}
    {% endblock %}

    <hr>
    {% block extjs %}
    {% endblock %}
</body>
</html>